What is considered as hearing impairment?

Hearing impairment is defined as inability of a person to hear properly. It may be total hearing loss (profound) or partial hearing loss and is due to some hearing defect either in one or both ears.

Hearing impairment may present in children in a variety of ways. It may be noticed by the parent or the school teacher that the child has difficulty in hearing.

What are the grades and types of hearing impairment?

Severity is classified into 5 categories (depends on pure tone audiometry test):

• Mild hearing loss.
• Moderate hearing loss.
• Moderate to severe hearing loss.
• Severe hearing loss.
• Profound hearing loss.

There are 3 types of hearing loss:

• Conductive hearing loss.
• Sensorineural hearing loss.
• Combined conductive and sensorineural hearing loss.

What causes hearing loss?

Causes are varied and include:

• Congenital, hereditary prenatal and abnormal fetal developmental causes (well recognized syndromes that are associated with hearing loss are Waardenburg’s syndrome, Alport’s syndrome, Klippel-Feil syndrome, Usher’s syndrome). They are born with no development of ear canal.
• Perinatal causes (events that occur just before or after delivery) such as severe jaundice, severe prematurity with extremely low birth weight.
• Infections such as that occurring during pregnancy, measles, repeated middle ear infection and infections of the brain.
• Drugs that affect hearing (kanamycin, gentamycin, streptomycin).
• Head injury.
• Prolonged contact with a loud noise.
• Holes in the ear drum.

When should hearing loss be suspected?

The following are indicators that the child may have hearing loss. He:

• Does not respond to sound even on extreme loud noise.
• Shows behavioural problems eg disobedience, either as attention seeking or not listening, tantrums, withdrawal or enuresis.
• Does not talk as expected according to chronological age.
• Has failure to develop a normal speech.
• Is slow in learning (learning disability).
• Underachieves.

Warning signs are:

• No words with meaning by 18 months.
• No sentences by 30 months.

What is hearing loss treated?

All high-risk children need to undergo hearing assessment. Treatment depends on the type, underlying cause and extent of hearing loss. Treatment may be medical or surgical.

Medical approach involves:

• Sessions with speech therapist.
• Wearing a hearing aid, a device that helps to magnify the sound and helps one to hear better.
• Using sign language in profound hearing loss where surgical approach will not give any benefit.

Surgical approach involves:

• Cochlear implant (for those who fail to respond to hearing aids). This is an electronic device that is implanted into the cochlea via an operation. However this device only works optimally if it is done before the child is 3 years old.

What type of rehabilitation can be offered to children with hearing impairment?

These children will need to be enrolled in:

• Special school.
• Special class in a normal school.
• Sessions with speech-language pathologist or therapist.

What can be done to prevent hearing loss?

Preventive measures include:

• Immunisation to prevent haemophilus meningitis and measles infections.
• Early screening for hearing loss in high risk children.
• Good and healthy life style to prevent recurrent ear infections.
• Regular hearing check.
• Use of decongestant for colds or runny nose.
• Do not force objects inside your ear canal including cotton buds as this will push the build up wax to go deeper causing impacted wax.